The present application relates to construction equipment and machines, such as cranes, excavators, and the like. In particular, the present application relates to a construction machines that include an operator's cab that can by repositioned for transportation of the construction machine.
Construction equipment, such as cranes or excavators, must often be moved from one job site to another. Moving a crane or an excavator can be a formidable task when the machine is large and heavy. For example, highway limits on vehicle-axle loads must be observed, and overhead obstacles can dictate long, inconvenient routings to the job site.
One solution to improving the mobility of large construction machines, such as cranes, is to disassemble them into smaller, more easily handled components. The separate components can then be transported to the new job site where they are reassembled.
Of course, there is a both a time and cost component to disassembling and reassembling these machines. Thus, it is desirable to limit the number of components that must be disassembled. Instead, it is sometimes sought to provide components that may be repositioned or repackaged from their original position in order to meet any size/height/weight limits on the roads over which the construction machine travels when relocating to a new work site.
One of the components that proves typically cumbersome is the operator's cab for the construction machine. Typically, the operator's cab is positioned in a location from which it can best view the area in which the construction machine is working. For example, it is important for a crane operator to have a relatively unobstructed view to the top, sides, and above and below a rotating bed of the crane. The requirement for such a view typically results in the operator's cab being positioned towards the front of the crane and perhaps offset to one side or the other. In addition, some cranes include operator's cabs and/or operator's seats that have an ability to tilt the front of the operator's cab or seat upward. Tilting the operator's cab or seat upward provides the crane operator with a better view of the crane's boom and/or the hook/load during operations. Upward tilting seats and/or cabs, however, do not improve an operator's visibility in those situations in which the rotating bed is elevated relative to the work area, such as when a crane is lowering something into a hole, such as a building foundation.
Positioning the operator's cab in a location that provides the operator with improved visibility, however, typically causes the rotating bed and operator's cab to be too wide, too heavy, and/or too tall for many highways and regions. In those instances, it would be necessary to remove the operator's cab and ship it separately from the rotating bed. As noted, this increases the time and cost for disassembly and reassembly, not least because of the numerous electronic, hydraulic, and mechanical control systems that are integrated into the operator's cab.
Others have attempted to solve the shipping problem by provided an operator's cab that rotates relative to the rotating bed from an operating position to a stowed position in such a way that the rotating bed and operator's cab are capable of being shipped together in a single load that meets any travel restrictions expected to be encountered. The rotating assembly that operates to rotate the operator's cab, however, typically is capable of only rotating the operator's cab in a single plane. Stated differently, the operator's cab remains in the same horizontal plane in both the operating position and the stowed position. This, in turn, potentially imposes restrictions on the height of the cab, its location, and other packaging requirements in order to still meet the travel restrictions.
In some instances, the height of the operator's cab is still too high relative to the travel restrictions once the operator's cab has been rotated. Prior solutions involve complex, multi-bar and multi-link mechanisms that would raise and lower the entire operator's cab relative to the rotating bed. Because of the requirement that the operator's cab pivot/rotate from an operating position to a stowed position, this mechanism typically could only be positioned on one side of the operator's cab and proximate the pivot. As a consequence, multi-bar and multi-link mechanisms typically are large in weight to support the torque generated by the weight of the cab, as well as being complex to manufacture and maintain.
Therefore, there is a need for a construction machine that includes a cab capable of tilting at least downward as well as preferably upward. In addition, there is a need for the operator's cab to be positionable between an operating position and a stowed position in which the operator's cab and associated vehicle frame and/or rotating bed meets any necessary travel height and width restrictions.